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East Ridge Trail



0.7 mile 1.2 kilometer point to point
49% Runnable


Ascent: 30' 9 m
Descent: -746' -227 m
High: 6,791' 2,070 m
Low: 6,047' 1,843 m


Avg Grade: 21% (12°)
Max Grade: 56% (29°)


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Trail shared by Megan W

A steep and rocky but popular way to access Mount Sanitas.

Megan W

Features Views · Wildflowers · Wildlife

Runner Notes

This trail is steep and can be treacherous to run either as a ascent or descent. The trail squeezes between 2-3 enormous boulders and passing other users can be tricky. Trees shade a section of trail near the top and snow takes a long time to melt here.


From the summit of Mount Sanitas, gingerly pick your way down large rock steps alternately heading east and south. This topmost section of trail is the steepest, so take your time and remember to give way to panting uphill users. Views east are great if you can take your eyes away from watching your footing.

The East Ridge Trail does indeed travel down the east spine of Mount Sanitas and its surface is rocky, rooty and uneven. Early on, the trail turns north and passes down through a shady wooded gully. In the winter this area holds snow for a long time, so savvy people slip on yaktrax to negotiate this short, steep section.

About mid-way down, keep an eye out for small green signs attached to logs that point the way through two areas with huge boulders. It is easy to lose the hidden trail here and some timid users may may prefer to scootch a couple of feet down rocks on their bum! Don't be put off by the idea of this, it is very doable.

Once the trail leaves the ridgeline, the switchbacks lengthen and the gradient mellows considerably. Views open up of the Sanitas Valley Trail below, with Bear Peak and the Flatirons becoming visible to the south. The East Ridge Trail ends at a junction with the choice to head north through neighborhoods to Linden Drive or join the Sanitas Valley Trail to return to the Centennial trailhead.

Flora & Fauna

Note that mountain lions and bears pass through this area and although rangers do their best to put up warning signs about recent activity, dawn and dusk are the times to be most aware.

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Sep 30, 2017
Michael Reschly
Jul 6, 2017
Jen McMurtrey
Jun 5, 2015
Wendy Tseng

Trail Ratings

  3.8 from 6 votes


  3.8 from 6 votes
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in Colorado


26 Views Last Month
1,304 Since Nov 7, 2014



Sunrise from Mt Saintas
Nov 3, 2017 near Boulder, CO
The top of Mount Sanitas looks out at the beauty of Boulder and the Flatirons.
Apr 12, 2017 near Boulder, CO
Looking east from the summit at sunrise.
Dec 2, 2018 near Boulder, CO
Arriving at the summit, just missed the sunrise.
Dec 2, 2018 near Boulder, CO
Sunrise (5:30).
Jul 17, 2019 near Boulder, CO
A view of the Dakota Ridge Trail and the wider Sanitas Valley Trail, as seen from the East Ridge Trail partway up Mt Sanitas.
Jul 1, 2019 near Boulder, CO


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